Stabilization of organic materials with aryl polyphosphites



ret t d Sept. 30, 1952 U I t 2 5 4 3 1, J 4; V e subject to gum formation, sludge formationtithe"" f fdrfiiatidn ofit-acids oind the formation" 'ee' 5 sdifdlihf com products unless there is incorporated therewith i s'r rLIzATroN o-F'bRGANIc MA'FRIALS WITH ARYLPOLYPHOSPHITES 1 S afnHard 01f Development Company, a corpovet y pel etsr v "No'nraw'inz; ""iiiiiiucationmvember 2, 1950,]

(01. zoo-45 5) structure is illustrated in tionable'l'eulbrfi'fiodisi :3 1:11 is i t. It is also known that synthetic rubbers undergo changes due to further polymerization or degra- 7: R R R dation due to depolymerization on exposure to air g (l) and consequently yield on vulcanization infliidtzigo 515F111 i,

at time of synthesis a compound whichstablfiies the-synthetic'rubb'er-bylargelypreventingoxida tiorig' -degradatidn andfoi dyblization of the chain molecules' 'presentdmthjepolymer'structureNat '"35 Where and are bmadly ic"hydrocar---- hqa elrg sh y tfifififf bb fsgr' if? ,bon radicals, which oan be difierent-ibif similar, -fg difi ering in the latter case in only one hydrogen tioxidant present irfthiihlcdriiitlt t 1 t finished rubber products remain stable toward e and one F TR andR can h be poly-aryl, 'alkaryl, fused aromatic ring radicals oxidation and heat during their useful life. v

with or without alkylfside chains, etc. Ether Certain simple aryl phosphites such as tri- 1o y phenyl phosphite are linown to be stabilizers for linkages may also bekn'esent m the polyalyl rubbery materials. These simple phosphites hdwl Thflese F QSQ e plained at ever are subject to ready hydrolysis to low moleca er length "j Whefein h products of ular weight products which tend to degrade the r i ul ir reactants are disclosed. rubber under many conditions. This ready hy- 4 It should be noted that the recurring struc- Formulq at a temperature of approximately 50 to 100 C. No catalyst need be employed and the reaction conveniently'is continued until one molecule of R f HX is evolved. The resulting product is then reo 5 acted with approximately an equimolar amount i, L of the di-hydric phenol at a temperature of approximately 50 to 300 C. This reaction takes Formula I] about three hours or longer and the lower temperature is employed during the early course 01 wherein 3 is natural number is 0 or but reaction with the temperature raised in the latter when is at least stages of the reaction. It is desirable to strip all It should be noted that each compound of this I-IX evolved during the reaction's course with a invention thus contains at least two phosphite dry inert gas such as nitrogen or other inert groups. It is this configuration which is believed ner so as to prevent rupturing of the molecule by to impart the desired characteristics to the prod- 15 HX. It is also desirable to carry out the reac. nets of this invention.

The complete chain of the condensation prod- 3 2 fig? g gfifgfigi i gf g g gg gig: 1 B h invention may be Visualized as ated phenols are employed. P n Fo l below: The following examples are given to illustrate R R this invention and include both the preparation I of the aryl polyphosphites of this invention and 0 O test results on their use as anti-oxidants.

1LO-R--O s -i-- 1 EXAIWPLE I 7 Formula III Preparation of polyphosphite B (see Table I where A is a Cl, Br, OH, OR or OR'OH radical V below) and A is a difierent or similar radical selected Dfiggbutylphenol 0245 mole) and 1:31; 0,245 from the same group ex p W 1/ is 0; n mole) were placed in a 500 cc. flask equipped latter case only, A is a H atom. with a reflux condenser and thermometer. The

e ydrlc phenols t at can be p y v o outlet of the condenser was attached to a sodium for the purpose of this invention are illustrated hydroxide mt trap. containing 0.245 mole y dibu lph P -hydr Xy di-ph n NaOH to measure evolved HCI. Heating wasacy monobenzyl hvdroquinone. a acomplished with a Glas-Col menu's-.1 The above p ny -p e p e o alp a and be a nap h mixture was heated slowly and allowed to reflux ma p-cre l, pr butyl phenol nd its at the P0151 boiling point ('76 c.) until reaction 0- and manalog m-, and D- thyl 131161101, was essentially complete. Reflux condensing terp 'py P1181101. yl P11911015, d P11611018, minated at 110 C. pot temperature. At this time, the me y yl e o s. the trimethyl p o the. NaOH was found to be essentially neutralized 0-, m-, and p-hydroxy diphenyl methane, etc. to phenolphthalein indicating complete reaction The 'di hy ri Phenols that can be employed 40 of the phenol withoneof the chloro groups in the r the purpose of this invention are illustrated PO13. The product wasthen cooled to room temby hydroquinone. 2-5, di tertiary butyl hydro perature and the, 2,5-ditertiary butyl-hydroquiquin s rc l, pyr ca't chol. p. p'-.d1- none (0.245 mole) added. Heating was continued droxy diphenyl. the various dihydroxyl diph nyl for 3 hours or more While the temperatures gradmethanes such as p-, p-dihydroxyl diphenyl uallyrose to about 300. C. HCl evolution con methane, the various dihydroxyl naphthalenes, tinued during this period. -.d p-hydr y p l) p pa -amyl y- After cooling the resulting product, it was disdroquinone; ring alkylated resorcinols, o-ethyl solved in 2 liters of diethyl ether. This-solution hydroquinone, o-octyl hydroquinone, o'-, o-di 'dov was washed twice with a sodium bicarbonate-sodecyl hydroquinone, etc. The di-hydric phenols, dium chloride water, solution and then washed wherein the hydroxyl radicals are para to each twice with distilled water. After separating the other, are particularly eiiective and desirable. ether layer and drying over anhydrous NazsOs,

The products of this invention can be prepared the ether was vstripped ofi'to a final temperatureby flrst condensing the mono-hydric phenol with of 225 C. An overall yieldvof 83.3 per cent was a .PIQ compound in approximately I equimolar obtained. a A q ratios, wherein X is a halogen radical selected A similar procedure was used in preparing the from the group consisting of Cl, Br and I radicals other materials listed in the TableI below:

TABLE I "Polyphosphites" RAW MATERIALS Product Phenolic, etc. I Moles.

CaHu Diisobutylphenohu- 0.245 Straw col d' I ggilroqulnonennln liquid, ry viscous Properties of the Product EXAMPLE I: 1% of the products B, G, and C of Table I above were tested for anti-oxidant efiect on raw Para:

cril (a butadiene-acrylonitrile synthetic rubber). Theresultsfollowz a a. -15 j TP ercent h'ei' in ti t-tr g er Aging Antioxidant-1% Addd' to Polymer 5 1 wk: 2 wks. 4 wks. 6.5 wks.

Product B 1 1 4 17 Product .l 1 2 3 3 Product G .1 0. 9 1.485 Phenyl beta naphthylamine, "2 26 48 Pare phenyl phenol 33 g 60 45 66 EXAMPT' LE 11:

1% of product G of Table I and a similar quantity of a well known commercial anti-oxidant 2,6-di-t-butyl-4-methylphenol were tested for anti-oxidant emcacy on cured Paracril. The results follow: 5 i I? pastimes:

i 11 III Ii III Unaged: 1- ensile Strength, 11-; 300% Modulus, end- III-Elongation Aged 6 Hours at 300 F.:

I-Tensiie Strength, 11- 300% Modulus, and III-Elongation Aged 16 Hours at 300 F.:

I--Tensile Strength, II 300% Modulus, and III-Elongation Thes'eldatashow that the physicals of the vulcanizates and the aging are-not adverselyafiected by the polyphosphites, whereas these additives are superior with respect to preventing 'gel formation and they also cause less discoloration. of the Paracril upon heating.

1 of product G of Table I and a'slmilar quan-vv tity of 2,6-di-t-butyll-methylphenol were compared as to their color stabilizing efiect on raw this, invention that the class of inhibitors in- 'dic at'ed' may be used to stabilize oxidation unzsta'bie" mixtures. i @hitflfi are particularly adapted for use with syn- The indicated aryl polyphosthetic'ester lubes, mineral oils, greases .iormed from metallic stearate and esters, rubbers, and

V. l wax polymer blends.

p It is also proposed the arylpolyphos phite anti-oxidants of this invention be employed to stabilize organic compounds such as mineral oils. synthetic ester lubricating oils, lubricating/ oils ,and particularly that they should be used to "ylpentadiene-lfi and the like; hence synthetic rubbers of {the above class include polymers of these materials and also*'copolymers prepared by the polymerization of monomer mixtures com-.-

prising a major proportion of such a polymeriza- 'ble diolefin and also containing a minorproportion of other mono'ethylenically unsaturated compounds copolymerizable with .the diolefin such as methyl acrylonitrile, methyl methacrylate, styrene, alpha methylstyrene, vinyl naphthalene, vinyl] ketoneanvinylidene chloride, diethyl fumarate, vinyl pyridine,.and the like. Natural vulcanized rubber also stabilized by the compounds of this invention.

The incorporation of the aryl polyphosphites with the synthetic rubber may. be. carried out Paracril aged for 10fdays at C. The sample stabilized with ZLG 'di-t-butyl-4-methylphenol turned a dark yellowfto brown color, whereas the polyphosphite caused little: discoloration, only a few light yellow spots being present in the aged polymer. 1 7

It is apparent from the above results that the products or this invention are-verygoodin preventing undesirabl'e gelformation." a matter of iact from 16 to 3 times less gelw'as formed than when phenyl beta naphthylamine was used. The latter has'always been considered one of the best stabilizers for uncured Paracril.

The compounds of this invention were tested compositions.

simply by adding the compound either in the pure form or in solution, suspension or emulsion to the solid synthetic rubber in a water dispersion, or during the milling operation, or ,to a latex containing the synthetic rubber dispersed in an aqueous medium. such as is ordinarily obtained by an emulsion polymerization process.

The compounds of this invention are, as pointed out above, extremely efiective in'Paracril, a copolymer comprising a major proportion, i. e.=, 85-50 parts, -of butadiene and a minor proportion,-i. e. 15-50 parts by. Weight, of acrylonitrile.

The compounds also stabilize blends o and lEfaracril. we p The amount of tliedndicatedaryl polyphosphite added-"to the normally oxid'izable material in order to prevent oxidation varies with differf Vinylite entina'terials. In general the amountthat has to be addedtothe normally oxidizable material represents only a, small proportion of the result- .-ing compositionsri. e. 0.003-5 wt. percent in most cases. Typical formulations are as follows with the weight per cent figure based on the total Lubricating oils-0.0a to 10% and preferably 1 to l 2% anti oxidant by weighti and also found to possess anti-oxidant activity on Rubbers and "plastics illto 5% -.by .weig ht synthetic esters, synthetic rubbers, lube oils, etc. It is to be seen from the above examplesjthat thecompoundsof this inventionprovidemarkekM- ly effective oxidation inhibition. As a result of 'rh fi diiets of this 'i ,ii'tiEii may be utilized conjunction with otheranti-oxidants in order to obtain desirable combinations o'f properties.

these tests, it is contemplated in accordance with Among the other anti-oxidant materials which offered merely as illustrations, since other derivatives can be prepared, and that modifications may be made without departing from the spirit of the invention.

What is claimed is:

1. As a new composition of matter, an aryl polyphosphite resinous condensation product produced by the reaction which comprises condensing an aromatic compound containing one hydroxyl group linked to the aromatic nucleus with a phosphorus compound having the formula PXa, wherein X is a halogen radical selected from the group consisting of Cl, Br and I radicals and condensing the resulting product with an aromatic compound having two OH groups linked to the aromatic nucleus, said condensation product containing the structural unit, wherein R and R are aromatic radicals and wherein a: is a natural number, 11 is a number selected from the group consisting of and 1, but when y is 0, x is at least two.

2. A composition as in claim 1, in which the monohydric phenol, the di-hydric phenol and the PX: are reacted in approximately equimolar proportions.

3. A composition as in claim 2, in which the dihydric phenol contains the hydroxyl groups para to each other.

4. A composition as in claim 1, in which the monohydric phenol is diisobutylphenol, and the di-hydric phenol is 2,5-ditertiarybutyl hydroquinone.

5. A composition as in claim 1, in which the monohydric phenol is p-hvdroxydiphenyl, and the di-hydric phenol is ditertiary butyl hydroquinone.

6. A composition as in claim 1, in which the monohydric phenol is diisobutylphenol and the di-hydric phenol is hydroouinone.

'1. A composition of matter comprising an organic material normally subject to oxidative changes containing a minor proportion effective as an anti-oxidant of an aryl polyphosphite resinous condensation product produced by the reaction which comprises condensing an aromatic compound containing one hydroxyl group linked.

to the aromatic nucleus with a phosphorus compound having the formula PXs, wherein X is a halogen radical selected from the group consisting of Cl, Br, and I radicals and condensing the resulting product with an aromatic compound having two OH groups linked to the aromatic nucleus, said resinousicondensation @rddllntf con;

taining the biennial). A

structural unit, wherein R and R are aromatic radicals and wherein an is a natural number, 11 is a number selected from 'thegroup consisting of 0 and 1 1, but wheny isl), :1: is at l'e'a's'tqtwo.

8. A stabilized synthetic frubber composition comprising a synthetic rubber having admixed therewith a minor proportion efiective 'asfiari anti structural unit, wherein R and R are aromatic radicals and wherein a: is a natural number, 11 is a number selected from the group consisting of 0 and 1, but when 11 is O, a: is at least two.

9. A synthetic rubber composition as in claim 8, in which the aryl polyphosphite is present in an amount of from 0.1 to 5 Wt. per cent.

10. A composition as in claim 9, in which the synthetic rubber is a butadiene, acrylonitrile synthetic rubber.

11. A stabilized synthetic rubber composition comprising a butadiene, acrylonitrile synthetic rubber having admixed therewith in an amount of from 0.1 to 5 wt. per cent of an aryl polyphosphite condensation product produced by the reaction which comprises condensing disobutyl phenol with PCls in approximately equimolar proportions and condensing the resulting product with 2,5-dietertiary butyl hydroquinone in approximately equimolar proportions, said resinous product containing the CsHrl CsHi'l 11 12 proximately equimolar proportions, said product '13. A composition as in claim 2, in whichth containingthe butadiene, acrylonitrile synthetic rubber comprises 85-50 parts by weight of butadiene an I 15-50 parts by weight of acrylonitrile.

5 JOSEPH F. NELSON No references cited.

structural unit.

9. J 0? JIIOl J sdim aodq s 21 A. L. 5 doiriw [mite-s91 r. .o0 quc IW l'msriqib grzianabn' 

1. AS A NEW COMPOSITION OF MATTER, AN ARYL POLYPHOSPHITE RESINOUS CONDENSATION PRODUCT PRODUCED BY THE REACTION WHICH COMPRISES CONDENSING AN AROMATIC COMPOUND CONTAINING ONE HYDROXYL GROUP LINKED TO THE AROMATIC NUCLEUS WITH A PHOSPHORUS COMPOUND HAVING THE FORMULA PX3, WHEREIN X IS A HALOGEN RADICAL SELECTED FROM THE GROUP CONSISITING OF CL, BR AND I RADICALS AND CONDENSING THE RESULTING PRODUCT WITH AN AROMATIC COMPOUND HAVING TWO OH GROPS LINKED TO THE AROMATIC NUCLEUS, SAID CONDENSATION PRODUCT CONTAINING THE 